进化规划-蚁群优化算法的构建并用于化工过程操作优化

经典蚁群优化（ACO）算法搜优效率高,但只适用于求解组合优化等离散问题.以搜索最优食物源为目标,并引入进化规划（EP）简洁的进化机制,用以改造ACO,使之适于连续问题.又将蚁群分工为全局和局部蚂蚁,分别引领个体进行全局探索式和局部挖掘式寻优,并在各个体上释放信息素,供蚁群共享,由此继承了ACO正反馈、互激励的优点,并在优进策略的支持下,构建为EP-ACO算法.经复杂测试函数的优化检验,显示出EP-ACO适于连续问题,且全局搜优效率高,对高维问题适应性强.将EP-ACO应用于二甲苯异构化装置的操作优化,取得了良好的效果,与其他方法相比,优越性明显.     

多变异遗传算法优化生物脱硫反应动力学模型参数

由于常规遗传算法(SGA)的全局寻优效率不高,用于复杂的生物脱硫反应动力学模型参数优化时效果欠佳,为此设计了一种新的多变异遗传算法(MGA)以提高全局寻优效率.MGA的改进措施包括散射变异、微扰变异和单纯形变异各算子的设计,多变异操作实施方案的制定,选择操作和交叉操作方式的选择和改进等.Shaffer′s F6函数和10维Alpine函数测试表明,与SGA相比,MGA的全局寻优效率大大提高.将MGA应用于红球菌DS-3脱除二苯并噻吩(DBT)的动力学模型参数优化,建立了更为准确的反应动力学模型.     

杂交蚁群系统的构建并用于反应动力学参数的估计

经典的蚁群算法模仿蚂蚁觅食,释放信息素,形成正反馈互激励机制,提高了全局寻优效率,但它只适用于离散问题.将解空间划分为小区域,用以承载信息素,设置全局与局部蚂蚁,引入遗传算法的种群和操作方式,以Powell寻优算子和最优解保留策略改造蚂蚁的智能活动与互激励机制,构建为杂交蚁群系统（hybrid ant colony system,HACS）,可用于求解连续优化问题.实例测试表明,HACS具有良好的全局寻优能力和稳定性,将HACS应用于2-氯苯酚在超临界水中氧化反应动力学参数的估算,获得了满意的结果.     

迭代遗传算法及其用于生物反应器补料优化

针对化工动态优化的数值求解问题,提出将迭代思想与遗传操作相结合,构建迭代遗传算法.算法首先对时间区间和控制搜索域实施离散化,进而应用遗传操作搜索离散问题的最优控制策略.逐步收缩搜索域并迭代以消减离散化带来的偏差,不断改善寻优结果,增强算法的稳健性.实例测试表明该算法简便、可行、高效,已成功地应用于Lee-Ramirez生物反应器补料流率的优化,运算结果优于文献值,显示了迭代遗传算法的优越性.迭代遗传算法尤其适用于系统的梯度信息不可得的情况.     

广义回归神经网络的改进及在延迟焦化建模中的应用

广义回归神经网络（GRNN）具有明确的概率意义,其参数大多能自动确定,仅光滑因子参数需优化估值.采用优进遗传算法（EGA）,将确定性与随机性寻优操作相融合,实现了高效全局搜优,它所基于的优进策略包括设计Powell寻优算子、改进交叉算子、自适应地调整交叉率和变异率等.以推广能力作为优化目标,所建的GRNN有很强的非线性拟合能力和优良的预报性能,将其成功地为延迟焦化过程建模,与径向基网络（RBFN）等相比,显示了明显的优势.     

混合粒子群优化算法及其应用

提出了一种通过改进全局最优位置粒子寻优策略而提高粒子群优化计算效率的混合粒子群优化算法。针对流程工业典型设备的状态跟踪预报等有计算时间限制的优化问题,混合粒子群优化算法在不改变原有粒子群粒子寻优策略的前提下,将粒子群整体已搜寻到的全局最优位置看作一个特殊的粒子,令该粒子执行梯度下降寻优的寻优策略。在粒子群的寻优迭代计算中增加全局最优位置粒子单独的梯度下降寻优过程,从而将粒子群优化算法的全局寻优特性与梯度下降算法的邻域寻优特性相结合,以提高粒子群优化算法的整体寻优效率,进而缩短寻优计算的时间。针对流程工业典型设备的实际应用表明,混合粒子群优化算法能够减少寻优迭代次数,进而缩短优化计算时间。     

优进策略支持的进化规划估计反应动力学参数

为准确估计反应动力学参数,在分析确定性优化方法与进化算法特性的基础上,提出了一种由优进策略支持的进化规划方法(EEP),它将确定性寻优的两点梯度法(TPG)引入随机的进化规划算法(EP)中。EEP将依概率调用TPG寻优操作,并相应地调整原有的随机性操作,包括简化变异操作、改进选择操作。测试结果表明EEP克服了TPG与EP的缺点,发扬了二者的优点,具有良好的全局寻优性能。将EEP方法成功地应用于2-氯苯酚在超临界水中氧化反应动力学参数的估计,效果良好,与其它方法相比,结果有所改进,显示出EEP方法的优越性。     

基于优进策略的遗传算法对重油热解模型参数的估计

针对常规遗传算法全局寻优效率偏低的弱点，提出了一种优进策略，用以改进常规遗传算法。该策略将从繁衍过程中获取进化信息，自适应地改进子代分布，适时引入确定性操作，以提高全局寻优性能。提出的相关技术包括维持种群的多样性、改进交叉算子、增加Powell寻优算子等。实例测试表明这种优进策略效果良好，并已成功地应用于重油热解三集总动力学复杂数学模型的非线性参数估计。     

用免疫量子粒子群算法优化控制决策表

提出用免疫量子粒子群算法优化控制决策表,使控制决策表的参数整定简单易行.其核心思想是将控制决策表作为算法中的粒子,以迭代搜索的方式寻找全局最优粒子.该算法的全局寻优能力强,计算机实现简单,可调参数少.模糊控制器和控制决策表的优化设计在SCON-2000模糊控制平台进行了工程化实现,并对水箱液位进行模糊控制.从对比结果中可以看出,优化了控制决策表以后,系统响应更快,精度更高,抗扰动能力更强.这表明了该算法在模糊控制器参数优化中的可行性.     

基于优进策略的差分进化算法及其化工应用

鉴于常规差分进化算法容易“早熟”,全局寻优能力有待提高,提出了基于优进策略的差分进化算法,利用种群繁衍的有用信息改进子代分布,并引入确定性寻优操作,以提高寻优性能.设计了单纯形寻优操作和重布操作,并调整有关概率等.测试表明新算法的全局寻优性能有明显改善,已成功地应用于铯-铷-钒系低温硫酸催化剂上SO2氧化反应模型参数的估计,效果良好.     

Insect antifeedant properties of anthranoids from the genusVismia

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.     

Direct observation of freeze-thaw instability of latex coatings via high pressure freezing and cryogenic SEM

Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively. There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized. High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing, and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually preserves suspension stability during freezing. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago, IL. Tied for first place in The John A. Gordon Best Paper Competition.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Bark and Ambrosia Beetles in the Southeastern US

In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures (release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species (Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles from the southeastern region of the US.     

Novel polyurethane coating technology through glycidyl carbamate chemistry

Glycidyl carbamate chemistry combines the excellent properties of polyurethanes with the crosslinking chemistry of epoxy resins. Glycidyl carbamate functional oligomers were synthesized by the reaction of polyfunctional isocyanate oligomers and glycidol. The oligomers were formulated into coatings with several amine functional crosslinkers at varying stoichiometric ratios and cured at different temperatures. Properties such as solvent resistance, hardness, and impact resistance were dependent on the composition and cure conditions. Most coatings had an excellent combination of properties. Studies were carried out to determine the kinetics of the curing reaction of the glycidyl carbamate functional oligomers with multifunctional and model amines. Detailed kinetic analysis of the curing reactions was also undertaken. The results indicated that the glycidyl carbamate functional group is more reactive than a glycidyl ether group. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, on October 27–29, 2004, in Chicago, IL.     

Highly moisture-proof polysilsesquioxane coating prepared via facile sol-gel process

A highly moisture-proof polysilsesquioxane coating was obtained from a new bis-silylated precursor, which was synthesized from 3-aminopropyltriethoxysilane (APTES) and m-xylylene diisocyanate (m-XDI) in tetrahydrofuran (THF) and verified by ¹H MAS NMR. For direct comparison purposes, an SiO₂ coating was also prepared by the Stöber method using tetraethoxysilane (TEOS) as the reactant. Interestingly, the coating obtained from the polysilsesquioxane sol exhibited a much higher moisture resistance capability than its counterpart, which was attributed to its more compact feature between nanoparticles as characterized by N₂ absorption experiment and transmission electron microscopy (TEM). Furthermore, its high transparency of about 92% showed potential for application in the protection of optical crystals.